<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>面向对象</title>
</head>
<body>
    <script>
        function getName(){
            console.log("4");
        }
        getName();
        function Foo(){
            console.log("2");
        }
        Foo();
        Foo(getName);
       
    </script>
</body>
</html>